Recently, display devices using a plasma display, a liquid crystal display, a field emission display and the like including a light emitting diode (hereinafter, it is abbreviated as LED (Light Emitting Diode)) have been generally known and have been widely employed together with those using a conventional CRT (Cathode Ray Tube), a discharge tube or the like, or in substitution for them.
However, in these display devices, a conversion efficiency of light is low, and, for example, as to LED elements, it is about 10% and most supplied power is to be converted to heat. Furthermore, the rise in temperature of the above-mentioned elements further decreases the conversion efficiency of light, thus to be the cause of reduction in reliability of elements and uneven brightness. In particular, in the case that elements of displaying colors (for example, elements of displaying a red color, blue color and green color) have different light conversion efficiencies, this fact is to be a primary factor of generation of irregular colors, and a problem exits in, e.g., the reduction in quality of images.
In the case of a display device using a light emitting element such as LED element, being different from the one that uses a normal CRT and the like, light emitting sources, that is, light emitting elements of which temperatures should be uniform are arranged normally at regular intervals on the entire surface of a display device. In addition, integrated circuits, for example, a driver IC, a logic IC, an FET, and a clock IC necessary for controlling the light emission of LED elements are a source of heat generation. Since these integrated circuits are disposed on a substrate avoiding an LED element, an interface, a capacitor and the like, they cannot be arranged at regular intervals, which will be the factor of generation of temperature distribution between the LED elements.
Therefore, it is required to suppress the rise in temperature of the elements and the temperature distribution between the elements with the use of some cooling unit. Conventionally, to cope with this, an attempt has been proposed, and in which a ventilation hole is formed in a display panel part that is provided to mold the LED so as to get through from its front face to its back face; as well as a cooling air having been taken in from outside using a fan cools a cell substrate functioning to drive the LED, and thereafter the cooling air is sent to the front face on the display panel side through the above-mentioned ventilation path, whereby heat having been radiated from the display cell is discharged to the outside. (For Example, Refer to Patent Document 1.)
In addition, another cooling system of a display has been proposed, and in which a partition plate is disposed in the proximity of the back of a light guide, whereby a channel of fluid that is adjacent to the back of the light guide is formed. (For example, refer to Patent Document 2.)
Patent Document 1: Japanese Patent Publication (unexamined) No. 293540/1998
Patent Document 2: Japanese Patent Publication (unexamined) No. 76286/2003